In observational studies, type 2 diabetes is associated with 2- to 4-fold higher risks of cardiovascular diseases (CVD). Using data from the China Kadoorie Biobank, we examined associations of genetically-predicted type 2 diabetes with CVD among ∼160,000 participants, to assess whether these relationships are causal. A type 2 diabetes genetic risk score (comprising 48 established risk variants) was associated with the presence of carotid plaque (OR 1.17 [95% CI 1.05, 1.29] per 1 unit higher log-odds of type 2 diabetes; n=6,819), and elevated risk of ischaemic stroke (IS) (1.08 [1.02, 1.14]; n=17,097), non-lacunar IS (1.09 [1.03, 1.16]; n=13,924) and major coronary event (1.12 [1.02, 1.23]; n= 5,081). There was no significant association with lacunar IS (1.03 [0.91, 1.16], n=3,173) or intracerebral haemorrhage (ICH) (1.01 [0.94, 1.10], n=6,973), although effect estimates were imprecise. These associations were consistent with observational associations of type 2 diabetes with CVD in CKB (p for heterogeneity>0.3), and with the associations of type 2 diabetes with IS, ICH and coronary heart disease in two-sample Mendelian randomisation analyses based on summary statistics from European population GWAS (p for heterogeneity>0.2). In conclusion, among Chinese adults, genetic predisposition to type 2 diabetes was associated with atherosclerotic CVD, consistent with a causal association.